Self-propagating reaction sintered magnesium aluminate spinel ramming mass and preparation method thereof

Abstract

The present application belongs to the technical field of refractory material, and discloses a self-propagating reaction sintering magnesium-aluminum spinel ramming material and a preparation method thereof. The ramming material comprises the following raw materials in mass fraction: 30-40 parts of spinel with a particle size of 3-6 mm, 5-15 parts of spinel with a particle size of 1-3 mm, 8-15 parts of magnesia with a particle size of less than 1 mm, 3-5 parts of silicon carbide with a particle size of less than 1 mm, 3-5 parts of silicon nitride powder, 2-5 parts of metal silicon powder, 8-12 parts of active alumina powder, 15-30 parts of magnesium peroxide powder, and 5-10 parts of metal aluminum powder, wherein the sum of the mass fractions of the above raw materials is 100 parts, and 1-2 parts of liquid binder is additionally added. The ramming material uses magnesium peroxide as the oxygen source to cause the aluminothermic reaction of metal aluminum, promotes the sintering of the material, uses silicon carbide and silicon nitride as the heat-conducting agent to rapidly transfer the released heat, uses alumina powder as the diluent to avoid the collapse caused by the excessive reaction heat stress, so that the ramming material successfully passes through the self-propagating reaction sintering, the sintering energy consumption is low, and the sintered product has excellent performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of refractory materials, and particularly relates to a self-propagating reaction sintered magnesium aluminate spinel ramming material and a preparation method thereof. BACKGROUND

[0002] Magnesium aluminate spinel is a series of compounds with the molecular formula MgAl2O4 in an isometric system, and a unit cell is composed of 32 cubic close-packed oxygen anions O 2- 16 A1 3+ and 8 magnesium ions Mg 2+ in octahedral interstices and 8 magnesium ions Mg in tetrahedral interstices. The magnesium aluminate spinel used in industry is all artificially synthesized, has a hardness of more than 9.0 Mohs, a melting point of 2250 DEG C, and a maximum use temperature of 1900 DEG C. This material is widely used in refractory materials due to its good slag corrosion resistance, thermal shock resistance and high high-temperature strength.

[0003] Chinese patent CN107879753A discloses a silicon carbide-magnesium aluminate spinel composite refractory material. The silicon carbide-magnesium aluminate spinel composite refractory material uses silicon carbide particles as aggregate, adopts fine or micro powder of magnesium aluminate spinel, aluminum oxide and magnesium oxide as a matrix, and adds an antioxidant. After mixing and forming various raw materials, drying, and firing under carbon-embedded or nitrogen atmosphere protection at a maximum firing temperature of 1450-1600 DEG C, a composite refractory material with SiC as the main crystal phase and magnesium aluminate spinel as the secondary crystal phase is obtained.

[0004] Chinese patent CN111704466A discloses a silicon carbide-magnesium aluminate spinel-aluminum composite refractory material. The main difference from CN107879753A is that the particle size range of the aluminum sol-coated metal aluminum powder added to the matrix is 10-45 microns, and the total mass of the raw materials is 2-8%. After machine pressing, the green body is fired at high temperature, and Al-O-N-C fiber reinforcement is formed inside the metal aluminum powder at a maximum temperature of 1500-1600 DEG C under carbon-embedded atmosphere, thereby improving the room temperature and high-temperature mechanical properties of the silicon carbide-magnesium aluminate spinel composite refractory material.

[0005] The above two methods both use high-temperature firing processes under carbon-embedded or nitriding atmosphere to prepare the silicon carbide-magnesium aluminate spinel composite refractory material. The firing process is complex, the firing temperature is high, the fuel consumption is large, and the cost is high. SUMMARY

[0006] The technical problem to be solved by the present invention is to address the deficiencies in the prior art and provide a self-propagating reaction sintered magnesium-aluminum spinel ramming material and a preparation method thereof. The ramming material uses magnesium peroxide as an oxygen source to cause metallic aluminum to undergo a thermite reaction, thereby promoting the sintering of the material. Silicon carbide and silicon nitride are used as thermal conductors to rapidly transfer the released heat. Alumina powder is used as a diluent to avoid thermal stress collapse caused by an overly intense reaction, thereby allowing the ramming material to be smoothly sintered through the self-propagating reaction, with low sintering energy consumption and excellent performance of the sintered product.

[0007] In order to solve the technical problem raised by the present invention, the present invention provides a self-propagating reaction sintered magnesia-alumina spinel ramming material, which includes the following raw materials in parts by mass: 30 to 40 parts of spinel with a particle size of 3 to 6 mm, 5 to 15 parts of spinel with a particle size of 1 to 3 mm, 8 to 15 parts of magnesia with a particle size of less than 1 mm, 3 to 5 parts of silicon carbide with a particle size of less than 1 mm, 3 to 5 parts of silicon nitride powder, 2 to 5 parts of metallic silicon powder, 8 to 12 parts of activated alumina powder, 15 to 30 parts of magnesium peroxide powder, and 5 to 10 parts of metallic aluminum powder, the total part by mass of the above raw materials being 100 parts, and 1 to 2 parts of a liquid binder are added.

[0008] In the above solution, the spinel is sintered spinel or fused spinel, and the sum of its Al2O3 and MgO contents is ≥95%.

[0009] In the above scheme, the magnesia is dead-burned magnesia or fused magnesia, and the MgO content is ≥92%.

[0010] In the above solution, the silicon carbide is black silicon carbide, and the SiC content is ≥98%.

[0011] In the above solution, the silicon nitride powder is β-Si3N4, the Si3N4 content is ≥98%, and the particle size is 1 to 10 μm.

[0012] In the above solution, the Si content of the metallic silicon powder is ≥98%, and the particle size is 20-80 μm.

[0013] In the above scheme, the Al2O3 content of the activated alumina powder is ≥99%, the particle size is ≤10μm, and the median particle size D 50 0.5~1.5μm.

[0014] In the above scheme, the MgO2 content of the magnesium peroxide powder is ≥99.9%, the particle size is ≤10μm, and the median particle size D 50 0.5~1.5μm.

[0015] In the above solution, the Al content of the metal aluminum powder is greater than 99%, and the particle size is ≤50 μm.

[0016] In the above solution, the mass ratio of the magnesium peroxide powder to the metallic aluminum powder is (3-3.2):1.

[0017] In the above scheme, the liquid binding agent is a viscous liquid organic matter.

[0018] Further, the liquid binding agent is one or more of tung oil, phenolic resin, tar, maltose, honey, etc.

[0019] The application also provides a preparation method of self-propagating reaction sintered magnesium-aluminum spinel ramming material, comprising the following steps:

[0020] 1) First, mix the magnesium peroxide powder, metal aluminum powder and a part of the liquid binding agent by primary ball milling, then add the silicon nitride powder, metal silicon powder and active aluminum oxide powder for secondary ball milling, take out the obtained mixture and add it into a stirrer, then add all the spinel, magnesia, silicon carbide and the remaining liquid binding agent to stir uniformly, to obtain the ramming material;

[0021] 2) Form or press the ramming material into bricks through a mold, naturally dry after demolding, then locally heat by flame spray gun or laser to initiate the aluminothermic reaction and realize the self-propagating overall sintering.

[0022] In the above scheme, the ball milling is carried out in a vacuum or inert atmosphere, the ball milling speed is 20-50 r / min, the primary ball milling time is 1-2 h, and the secondary ball milling time is 2-3 h.

[0023] In the above scheme, the ball milling is carried out in a ball mill with a cooling device to ensure that the material temperature is ≤60℃ during the ball milling process.

[0024] In the above scheme, the stirring speed of the stirrer is 30-45 r / min, and the stirring time is 30-60 min.

[0025] In the above scheme, the liquid binding agent is added in two times, the first time adding amount is 30-50% of the total mass, and the second time adding amount is 50-70% of the total mass.

[0026] In the above scheme, the natural drying time is 12-36 h.

[0027] In the above scheme, the local heating temperature is >1250℃, and the time is 5-10 s.

[0028] In the above scheme, the volume density of the sintered ramming material is 2.95-3.05 g / cm 3 , the apparent porosity is 14.5-16.5%, the cold crushing strength is 70-100 MPa, the hot modulus of rupture is >1680℃, and the 1100℃ water cooling thermal shock resistance is 20-25 times.

[0029] The technical concept of the application is as follows:

[0030] Aluminothermic reaction is a redox reaction between aluminum powder and metal oxide, which is a violent exothermic reaction. When the temperature exceeds 1250℃, the aluminum powder is oxidized violently, and a large amount of heat is released. The temperature of this exothermic reaction can reach more than 3000℃. Aluminothermic reaction is very rapid and has a short action time, and has a self-propagating characteristic. If it can be applied to magnesium aluminate spinel ramming material, it can significantly reduce the sintering energy consumption, but there are problems. If the aluminothermic reaction is simply used in dense refractory materials, the heat cannot be smoothly discharged, which will cause the material to crack and even explode. In addition, the added metal oxide and the generated metal have relatively low melting points, which affect the performance of the refractory material. The application adopts magnesium peroxide as the oxygen source to generate magnesium oxide and alumina as the refractory phase, and the spinel produced by the reaction of magnesium oxide and alumina is also a refractory phase. The active alumina powder is used to dilute and treat the aluminothermic agent to reduce the reaction intensity. At the same time, the active alumina powder can synthesize spinel with the generated magnesium oxide. Silicon carbide and silicon nitride are used as heat-conducting media to rapidly transfer the released heat and maintain the uniform temperature of the entire construction body, so that the entire construction body can smoothly undergo self-propagating reaction to solve the above problems.

[0031] Compared with the prior art, the application has the following beneficial effects:

[0032] 1) Magnesium peroxide is used as the oxygen source to prepare an aluminothermic agent with aluminum powder. The aluminothermic reaction occurs at >1250℃ to generate alumina and magnesium oxide, and further synthesize spinel, while releasing a large amount of heat. The purpose of sintering is achieved through the reaction exothermic of the material itself.

[0033] 2) Silicon carbide and silicon nitride are used as heat-conducting media to uniformly conduct the heat released by the reaction to the entire ramming structure to occur self-propagating reaction, and the material is sintered simultaneously inside and outside.

[0034] 3) The metal aluminum powder, metal silicon powder and beta-Si3N4 grow sialon whiskers along the beta-Si3N4 needle-shaped crystals under the oxygen partial pressure generated by the decomposition of magnesium peroxide, and are solid-solution connected with the surface of silicon carbide to form a network structure, which further strengthens the material and improves the thermal shock stability.

[0035] 4) The active alumina powder is mixed with the aluminothermic agent to dilute and disperse the aluminothermic agent, reduce the reaction intensity of the aluminothermic agent, and avoid the material cracking caused by the local temperature being too high. At the same time, the active alumina powder is in full contact with the magnesium peroxide, which can react with the magnesium oxide generated by the decomposition of the magnesium peroxide to form spinel in the matrix in situ, and a certain volume expansion occurs to compensate for the shrinkage of the material caused by the melting and sintering of the added powder at high temperature, thereby improving the density of the material.

[0036] 5) The MgO on the surface of the magnesia reacts with the active alumina to form spinel, which directly combines with the periclase in the magnesia and the spinel in the matrix, thus reducing the porosity and increasing the strength of the material. DETAILED DESCRIPTION

[0037] In order to better understand the present application, the following examples are further illustrated the content of the present application, but the content of the present application is not limited to the following examples.

[0038] In the following examples, the sintered spinel or the fused spinel selected all satisfy the sum of Al2O3 and MgO content ≥ 95%; the dead-burned magnesia or the fused magnesia selected all satisfy the MgO content ≥ 92%; the silicon carbide is black silicon carbide, the SiC content ≥ 98%; the silicon nitride powder is β-Si3N4, the Si3N4 content ≥ 98%, the particle size is 1-10 μm; the silicon metal powder has the Si content ≥ 98%, the particle size is 20-80 μm; the active alumina powder is made by heating and dehydrating aluminum hydroxide, the Al2O3 content ≥ 99%, the particle size ≤ 10 μm, and the median particle size D50 is 0.5-1.5 μm; the magnesium peroxide powder has the MgO2 content ≥ 99.9%, the particle size ≤ 10 μm, and the median particle size D50 is 0.5-1.5 μm; the aluminum metal powder has the Al content ≥ 99%, the particle size ≤ 50 μm. 50 50

[0039] Example 1

[0040] A self-propagating reaction sintered magnesia-alumina spinel ramming mixture comprises the following raw materials in mass fraction: 30 parts of fused spinel with the particle size of 3-6 mm (not including 6 mm), 10 parts of fused spinel with the particle size of 1-3 mm (not including 3 mm), 10 parts of dead-burned magnesia with the particle size of <1 mm, 3 parts of silicon carbide with the particle size of <1 mm, 5 parts of silicon nitride powder, 2 parts of silicon metal powder, 8 parts of active alumina powder, 24 parts of magnesium peroxide powder, 8 parts of aluminum metal powder, and 2 parts of tar.

[0041] A preparation method of a self-propagating reaction sintered magnesia-alumina spinel ramming mixture comprises the following steps:

[0042] 1) First, put 24 parts of magnesium peroxide powder, 8 parts of aluminum metal powder and 1 part of tar into a ball mill, fill the ball mill with argon protection and control the rotating speed to 20 r / min, ball mill and mix for 2 h, then add 5 parts of silicon nitride powder, 2 parts of silicon metal powder and 8 parts of active alumina powder and continue to ball mill and mix for 1 h, and the ball milling process is ensured by a cooling device to ensure that the material temperature is ≤ 60℃; take out the obtained mixture and add it into a stirrer, then add 30 parts of fused spinel with the particle size of 3-6 mm, 10 parts of fused spinel with the particle size of 1-3 mm, 10 parts of dead-burned magnesia with the particle size of <1 mm, 3 parts of silicon carbide with the particle size of <1 mm and 1 part of tar, and stir at 30 r / min for 45 min to obtain the ramming mixture.​​

[0043] 2) Put the ramming material into a mold of 230 mm x 114 mm x 65 mm, pressurized forming under 100 MPa pressure, and after demolding, naturally place for 24 h drying, then place on the alumina hollow ball brick, focus irradiation for 5 s with a laser igniter, so that the irradiation point temperature reaches above 1250℃, initiate the aluminothermic reaction, realize self-propagating bulk sintering.

[0044] Example 2

[0045] A self-propagating reaction sintering magnesia-alumina spinel ramming material, comprising the following mass fractions of raw materials: 32 parts of fused spinel with a particle size of 3-6 mm (not including 6 mm), 8 parts of fused spinel with a particle size of 1-3 mm (not including 3 mm), 12 parts of dead-burned magnesia with a particle size of <1 mm, 5 parts of silicon carbide with a particle size of <1 mm, 5 parts of silicon nitride powder, 4 parts of metal silicon powder, 10 parts of active alumina powder, 18 parts of magnesium peroxide powder, 6 parts of metal aluminum powder, and 1 part of phenolic resin.

[0046] A preparation method of a self-propagating reaction sintering magnesia-alumina spinel ramming material, comprising the following steps:

[0047] 1) First, put 18 parts of magnesium peroxide powder, 6 parts of metal aluminum powder, and 0.4 parts of phenolic resin into a ball mill, fill argon gas into the ball mill and control the rotation speed to 30 r / min, ball mill and mix for 1 h, then add 5 parts of silicon nitride powder, 4 parts of metal silicon powder, and 10 parts of active alumina powder and continue to ball mill and mix for 2 h, and the ball milling process is ensured that the material temperature is ≤60℃ through a cooling device; take out the obtained mixture and add it into a stirrer, then add 32 parts of fused spinel with a particle size of 3-6 mm, 8 parts of fused spinel with a particle size of 1-3 mm, 12 parts of dead-burned magnesia with a particle size of <1 mm, 5 parts of silicon carbide with a particle size of <1 mm, and 0.6 parts of phenolic resin, and stir at 35 r / min for 60 min to obtain a ramming material;

[0048] 2) Put the ramming material into a mold of 160 mm x 40 mm x 40 mm, compactly ramming and forming, and after demolding, naturally place for 24 h drying, then place on the spinel sand, and use a flame spray gun to point and spray flame, so that the local temperature reaches 1250℃ and maintains for 8 s, initiate the aluminothermic reaction, realize self-propagating bulk sintering.

[0049] Example 3

[0050] A self-propagating reaction sintered magnesia-alumina spinel ramming material comprises the following raw materials in parts by mass: 40 parts of sintered spinel with a particle size of 3-6 mm (excluding 6 mm), 5 parts of sintered spinel with a particle size of 1-3 mm (excluding 3 mm), 8 parts of fused magnesia with a particle size of less than 1 mm, 3 parts of silicon carbide with a particle size of less than 1 mm, 5 parts of silicon nitride powder, 2 parts of metallic silicon powder, 10 parts of activated alumina powder, 20 parts of magnesium peroxide powder, 7 parts of metallic aluminum powder, and 2 parts of tung oil.

[0051] A method for preparing a self-propagating reaction sintered magnesia-alumina spinel ramming material comprises the following steps:

[0052] 1) First, 20 parts of magnesium peroxide powder, 7 parts of metallic aluminum powder and 0.8 parts of tung oil are placed in a ball mill, and helium protection is filled into the ball mill and the speed is adjusted to 40 r / min. The ball mill is mixed for 2 hours, and then 5 parts of silicon nitride powder, 2 parts of metallic silicon powder and 10 parts of activated alumina powder are added and the ball milling is continued for 1 hour. The material temperature is ensured to be ≤60° C. by a cooling device during the ball milling process; the obtained mixture is taken out and added to a blender, and then 40 parts of sintered spinel with a particle size of 3 to 6 mm, 5 parts of sintered spinel with a particle size of 1 to 3 mm, 8 parts of fused magnesia with a particle size of less than 1 mm, 3 parts of silicon carbide with a particle size of less than 1 mm and 1.2 parts of tung oil are added, and the mixture is stirred at 40 r / min for 40 minutes to obtain a ramming material;

[0053] 2) Place the ramming material in a mold of 230mm×114mm×65mm, press it into bricks with a brick press, let it dry naturally for 24 hours after demolding, then place it on corundum sand, and use a flame spray gun to spray flame at a fixed point to make the local temperature reach 1250℃ and maintain it for 8s to induce thermite reaction and achieve self-propagating overall sintering.

[0054] Example 4

[0055] A self-propagating reaction sintered magnesia-alumina spinel ramming material comprises the following raw materials in parts by mass: 36 parts of sintered spinel with a particle size of 3-6 mm (excluding 6 mm), 6 parts of sintered spinel with a particle size of 1-3 mm (excluding 3 mm), 8 parts of dead-burned magnesia with a particle size of less than 1 mm, 4 parts of silicon carbide with a particle size of less than 1 mm, 3 parts of silicon nitride powder, 3 parts of metallic silicon powder, 10 parts of activated alumina powder, 23 parts of magnesium peroxide powder, 7 parts of metallic aluminum powder, and 1 part of honey.

[0056] A method for preparing a self-propagating reaction sintered magnesia-alumina spinel ramming material comprises the following steps:

[0057] 1) First, put 23 parts of magnesium peroxide powder, 7 parts of aluminum powder and 0.3 parts of honey into a ball mill, fill the ball mill with neon gas protection and control the rotating speed at 50 r / min, ball mill mix for 2h, then add 3 parts of silicon nitride powder, 3 parts of metal silicon powder and 10 parts of active alumina powder and continue to ball mill mix for 1h, the ball milling process is ensured that the material temperature is ≤60℃ through the cooling device; take out the obtained mixture and add it into a stirrer, then add 36 parts of sintered spinel with particle size of 3-6mm, 6 parts of sintered spinel with particle size of 1-3mm, 8 parts of dead-burned magnesia with particle size of <1mm, 4 parts of silicon carbide with particle size of <1mm and 0.7 parts of honey, stir at 45 r / min for 40 min to obtain ramming material;

[0058] 2) Put the ramming material into a mold of 230mmx114mmx65mm, press it into a brick with a brick press, and then naturally place it for 24h drying after demolding, then place it on magnesia, and use a flame spray gun to spray a flame at a fixed point to make the local temperature reach 1250℃ and maintain for 8s to initiate an aluminum thermal reaction and realize self-propagating overall sintering.

[0059] Comparative Example 1

[0060] The difference between Comparative Example 1 and Example 1 is only that the silicon nitride powder used is α-Si3N4.

[0061] Comparative Example 2

[0062] The difference between Comparative Example 2 and Example 1 is only that the amount of magnesium peroxide powder is increased to 30 parts.

[0063] Comparative Example 3

[0064] The difference between Comparative Example 3 and Example 1 is only that the amount of aluminum powder is increased to 11 parts.

[0065] Comparative Example 4

[0066] The difference between Comparative Example 4 and Example 2 is only that no silicon nitride powder and metal silicon powder is added, and the amount of silicon carbide with particle size of <1mm is increased to 14 parts.

[0067] Comparative Example 5

[0068] The difference between Comparative Example 5 and Example 3 is only that 8 parts of electrically fused magnesia with particle size of <1mm is replaced by 8 parts of sintered spinel with particle size of <1mm.

[0069] Comparative Example 6

[0070] The difference between Comparative Example 6 and Example 4 is only that 10 parts of active alumina powder is replaced by 10 parts of active magnesia with the same particle size.

[0071] The volume density, normal temperature compressive strength, load softening temperature and thermal shock resistance of the magnesium-aluminum spinel ramming mixture of each example and the comparative example were detected according to GB / T 4513.6-2017. The results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] From the data of the magnesium-aluminum spinel fired bricks in Example 1, Example 2, Example 3, Example 4 and the comparative example, it can be seen that the aluminum thermal reaction sintered magnesium-aluminum spinel ramming mixture provided by the application has high volume density and load softening temperature due to self-propagating bulk sintering, the thermal shock resistance is significantly improved due to the addition of silicon carbide, and the compressive strength obtained by self-propagating sintering is not inferior to that of finished product bricks. Compared with magnesium-aluminum spinel bricks, the production of refractory bricks or ramming mixture by this method does not need to consume time and energy to sinter the product, saves energy consumption of refractory brick sintering loss, and can greatly improve the production efficiency.

[0076] The above examples are merely examples for clearly illustrating but not limiting the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art, and all the embodiments do not need to be exhausted here, and thus the obvious changes or variations still fall within the protection scope of the application.

Claims

1. A self-propagating reaction sintered magnesium aluminate spinel ramming mass, characterized in that, The raw materials include the following quality parts: spinel with particle size of 3-6mm 30-40 parts, spinel with particle size of 1-3mm 5-15 parts, magnesia with particle size of <1mm 8-15 parts, silicon carbide with particle size of <1mm 3-5 parts, silicon nitride powder 3-5 parts, metal silicon powder 2-5 parts, active alumina powder 8-12 parts, magnesium peroxide powder 15-30 parts, metal aluminum powder 5-10 parts, the sum of the quality parts of the above raw materials is 100 parts, and 1-2 parts of liquid binder is additionally added.

2. The self-propagating reaction sintered magnesium aluminate spinel ramming mass according to claim 1, characterized in that, The mass ratio of the magnesium peroxide powder to the metal aluminum powder is (3-3.2):

1.

3. The self-propagating reaction sintered magnesium aluminate spinel ramming mass as claimed in claim 1, wherein, The spinel is sintered spinel or fused spinel, the sum of the Al2O3 and MgO contents of which is ≥95%; the magnesia is dead-burned magnesia or fused magnesia, the MgO content of which is ≥92%; the liquid binder is one or more of tung oil, phenolic resin, tar, maltose, and honey.

4. The self-propagating reaction sintered magnesium aluminate spinel ramming mass as claimed in claim 1, wherein, The silicon carbide is black silicon carbide, the SiC content of which is ≥98%; the silicon nitride powder is β-Si3N4, the Si3N4 content of which is ≥98% and the particle size of which is 1-10μm; the metal silicon powder has a Si content of ≥98% and a particle size of 20-80μm.

5. The self-propagating reaction sintered magnesium aluminate spinel ramming mass as claimed in claim 1, wherein, The active alumina powder has an Al203 content of > 99%, a particle size of < 10 μm, and a median particle size D50 of 0.5-1.5 μm; the magnesium peroxide powder has an MgO2 content of > 99.9%, a particle size of < 10 μm, and a median particle size D50 of 0.5-1.5 μm; and the metallic aluminum powder has an Al content of > 99%, a particle size of < 50 μm. 50 The active alumina powder has an Al203 content of > 99%, a particle size of < 10 μm, and a median particle size D50 of 0.5-1.5 μm; the magnesium peroxide powder has an MgO2 content of > 99.9%, a particle size of < 10 μm, and a median particle size D50 of 0.5-1.5 μm; and the metallic aluminum powder has an Al content of > 99%, a particle size of < 50 μm. 50 The active alumina powder has 6. A method for producing a self-propagating reaction sintered magnesium aluminate spinel ramming mass according to any one of claims 1 to 5, characterized in that, The method includes the following steps: 1) first, the magnesium peroxide powder, the metal aluminum powder, and a part of the liquid binder are subjected to primary ball milling mixing, then the silicon nitride powder, the metal silicon powder, and the active alumina powder are subjected to secondary ball milling mixing, the obtained mixture is taken out and added into a stirrer, all the spinel, the magnesia, the silicon carbide, and the remaining liquid binder are added and stirred uniformly to obtain ramming material; 2) the ramming material is formed or pressed into bricks through a mold, naturally dried after demolding, then locally heated by a flame spray gun or a laser to initiate an aluminum thermal reaction and realize self-sustaining overall sintering.

7. The method of producing self-propagating reaction sintered magnesium aluminate spinel ramming mass according to claim 6, characterized in that, The temperature of the local heating is >1250℃, and the time is 5-10s.

8. The method of claim 6, wherein the self-propagating reaction sintered magnesium aluminate spinel ramming mass is prepared by the steps of: The volume density of the ramming material after sintering is 2.95-3.05 g / cm 3 , the apparent porosity is 14.5-16.5%, the cold crushing strength is 70-100 MPa, the load softening temperature is >1680 DEG C, and the thermal shock resistance of water cooling at 1100 DEG C is 20-25 times.

9. The method of claim 6, wherein the self-propagating reaction sintered magnesium aluminate spinel ramming mass is prepared by the steps of: The ball milling is performed under vacuum or inert atmosphere, the ball milling rotation speed is 20-50r / min, the primary ball milling time is 1-2h, the secondary ball milling time is 2-3h, and the material temperature during the ball milling is ≤60℃.

10. The method of claim 6, wherein the self-propagating reaction sintered magnesium aluminate spinel ramming mass is prepared by the steps of: The liquid binder is added in two times, the first time amount is 30-50% of the total mass, and the second time amount is 50-70% of the total mass.

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